public void AddBubble(ChatBubble bubble)
{
var root = discussion.Root [0];
if (bubble.IsLeft) {
LeftThinking = false;
if (RightThinking) {
root.Insert (root.Count - 1, bubble);
} else {
root.Add (bubble);
}
} else {
RightThinking = false;
if (LeftThinking) {
root.Insert (root.Count - 1, bubble);
} else {
root.Add (bubble);
}
}
}